Extinguisher

ABSTRACT

An extinguisher includes a compressed-gas generator for fighting fire and incipient explosions, and the extinguisher includes at least one rupture diaphragm having a rupture joint, in order to seal the extinguishing-agent vessel. In its center, the rupture diaphragm has a planar surface or a depression, which causes the rupture joint to simultaneously open at its entire circumference, in order for the extinguishing agent to escape in an axially symmetric manner.

FIELD OF THE INVENTION

The present invention relates to an extinguisher for fighting fire andincipient explosions, the extinguisher including at least one rupturediaphragm, which seals an extinguishing-agent vessel and has a rupturejoint.

BACKGROUND INFORMATION

To fight fire and suppress incipient explosions which are caused byflour dust, coal dust, or solvent vapors, one normally uses vessels thatare filled with an extinguishing agent (usually extinguishing powder)and are permanently under pressure. In an emergency, these blow theextinguishing agent through a quick-opening valve, into the space whereextinguishing is required.

An extinguisher for fighting incipient explosions is described in GermanPublished Patent Application No. 195 44 399, where a tubularextinguishing-agent vessel is sealed on the inside and outside by flatrupture diaphragms. In the interior chamber adjacent to the innerrupture diaphragm, a compressed-gas generator is provided, the generatedpropellant gas of which ruptures the diaphragms and then expels theextinguishing agent. This extinguisher does not often achieve goodresults, since the rupture diaphragms seldom burst open in the center,or in an axially symmetric manner. Instead, the diaphragms rupture at apoint outside their center, which causes the expelled extinguishingagent to be dispersed in a considerably asymmetric manner. However, itis necessary to expel all of the extinguishing agent in a uniformmanner, in order to attain an optimum spray pattern and, thus, successin extinguishing.

In addition, German Published Patent Application No. 42 24 184 describesan extinguisher, where the extinguishing-agent vessel is sealed on theoutside by a convex rupture diaphragm, which is provided with circularand radial rupture joints. This diaphragm already opens at a pressure of0.1 to 1.0 bar above atmospheric pressure. Connected to theextinguishing-agent vessel is a compressed-gas generator, which, inresponse to being triggered, mixes the extinguishing agent together withthe compressed gas and sprays this mixture into the space where theextinguishing is to take place. In order for the extinguishing agent tohave a rapid effect, it may be more favorable for the extinguishingagent to only be dispersed after it is expelled from the vessel. Theshape of the diaphragm used also does not allow one to compensate forthe change in the extinguishing-agent volume as a function of thetemperature.

Other conventional extinguishers include rupture diaphragms that arespherically shaped so as to be inwardly concave in the direction of thecompressed-gas generator, and are provided with a rupture joint. Theserupture diaphragms bulge in response to pressure applied by the gasgenerator or thermally induced expansion, at some point that, generally,is not at the center of the diaphragms, but rather at an arbitraryposition on the spherical diaphragm surface. The bulge extends to theother side in the form of an inversion and results in a rupture jointrupturing off-center. This causes the extinguishing agent to bedischarged in a nonuniform manner.

Therefore, it is an object of the present invention to provide a rupturediaphragm for an extinguisher of the type mentioned above, so as toeliminate the above-mentioned disadvantages and cause the rupturediaphragm to burst open in the center, and thus uniformly disperse theextinguishing agent.

SUMMARY

The foregoing object is achieved by providing an extinguisher asdescribed herein. An advantage of the rupture diaphragm according to thepresent invention is that the planar surface or the depression in thecenter of the rupture diaphragm allows the diaphragm to be easilyinverted in the case of pressure being applied, without local bulgingoccurring. In this context, the rupture diaphragm behaves like a cupspring. In addition, the rupture diaphragm configured according to thepresent invention may compensate for thermal expansion of theextinguishing agent, since the planar surface or the depression in thecenter of the diaphragm is elastic in its movement in the axialdirection.

A further advantage results from the circular shape of the planarsurface in the center of the rupture diaphragm, in that a uniform loaddistribution is achieved in response to an applied pressure. Thissupports a uniform inversion of the diaphragms and prevents them frombulging on the side. The inverting procedure causes the rupture jointprovided on the edge of the rupture diaphragm to weaken prior tobreaking, so that the actual rupturing event occurs simultaneously onthe entire circumference, and the extinguishing agent is expelled in auniform manner.

An example embodiment of the extinguisher according to the presentinvention is described in detail below and is illustrated in the drawingin a schematically simplified manner.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates an extinguisher having concavediaphragms according to the related art.

FIG. 2 is a schematic cross-sectional view of an extinguisher cartridgehaving a planar center of the diaphragm.

FIG. 3 is a schematic cross-sectional view of an extinguisher cartridgehaving a central depression.

FIG. 4 is a schematic view of an inverted rupture diaphragm.

DETAILED DESCRIPTION

Illustrated in FIG. 1 is an extinguisher 1, which is constructed in aconventional manner and contains a pyrotechnic gas generator 2. Rupturediaphragms 3 and 4, which are concave with respect to pyrotechnic gasgenerator 2, i.e., curved in the direction of the gas generator, sealextinguishing-agent cartridge 5 so that extinguishing agent 6 cannotescape. Rupture diaphragms 3 and 4 are spherically shaped and haverupture joints in their diaphragm surfaces. In the case of pressurebeing applied, such rupture diaphragms bulge at some randomly determinedpoint or at a weak point in the material. In the case of a distinctbulge, the nearest rupture joint begins to break.

In order to prevent such an occurrence, the present invention providesforming the rupture diaphragms in a manner illustrated in FIG. 2. Inthis case, the center of rupture diaphragms 7 a and 7 b is in the formof a flat surface. Situated at the edge of rupture diaphragm 7 b is therupture joint 8 b that is impressed about the circumference.Temperature-dependent volume fluctuations are compensated for with theaid of the central, planar surface, by its elastic movement in thedirection of main axis A of extinguisher 1. In the case ofcompressed-gas generator 2 being triggered, the two diaphragms 7 a and 7b are simultaneously inverted, and the rupture joints 8 a and 8 bweakened by the inversion pull apart.

As illustrated in FIG. 3, rupture diaphragms 9 a and 9 b are configuredto be convex in their central region, i.e., curved away from thecompressed-gas generator. This shape of the diaphragms has a positiveeffect in centrally focusing the pressure applied by gas generator 2.

FIG. 4 illustrate the procedure of inverting the two rupture diaphragms7 a and 7 b illustrated in the resting state in FIG. 2, by the action ofthe applied gas pressure (arrows). During the inversion procedure,rupture joints 8 a and 8 b are first subjected to lateral flexure andthen tensile stress. The rupture simultaneously occurs along the ruptureline of the two rupture joints 8 a and 8 b. The resting position ofright rupture diaphragm 7 b is indicated in FIG. 4 by a dashed line.

What is claimed is:
 1. An extinguisher for fighting fire and incipientexplosions, comprising: a device configured to generate compressed gas;an extinguishing-agent vessel; and at least one rupture diaphragmsealing the extinguishing-agent vessel and including a rupture joint,the rupture diaphragm curved in a direction of the device configured togenerate compressed gas, the diaphragm including one of a central,planar surface and a depression curved away from the device configuredto generate compressed gas; wherein the central, planar surface includesa circular boundary.
 2. The extinguisher according to claim 1, whereinthe rupture joint is embodied circumferentially.
 3. An extinguisher forfighting fire and incipient explosions, comprising: a device configuredto generate compressed gas; an extinguishing-agent vessel; and at leastone rupture diaphragm sealing the extinguishing-agent vessel andincluding a rupture joint, the rupture diaphragm curved in a directionof the device configured to generate compressed gas, the diaphragmincluding one of a central, planar surface and a depression curved awayfrom the device configured to generate compressed gas; wherein therupture joint is embodied circumferentially at an edge of the at leastone rupture diaphragm; wherein the central, planar surface includes acircular boundary.